1. Field of the Invention
This invention relates to a resin forming nozzle device in which a surface lubricant (e.g., silicone oil) having mold release properties is continuously supplied to the resin forming nozzle face, and to a resin forming method using the same device.
2. Description of the Prior Art
When a synthetic fiber, as an example of formed resin products, is spun, oligomer of the resin or products resulting from the gradual degradation of a surface lubricant applied to the spinneret face may accumulate on the spinneret face from which resin filaments emerge, especially around the spinning orifices thereof. This may cause the spun filaments to be bent or broken. When the spun filaments are bent or broken, the spinning of the synthetic fiber must be discontinued to correct (or clean) the spinneret face. This requires much labor and also causes a significant reduction in production efficiency.
In order to solve the above-described problem, attempts have been made to modify the material of the spinneret and/or the longitudinal sectional shape of the spinning orifices or to introduce a surface lubricant continuously to the spinneret face. For example, Japanese Patent Publication No. 11823/'68 discloses a spinning method in which the spinneret face is inclined and a surface lubricant is continuously introduced to the spinneret face. In this method, however, the lengths of the spinning orifices vary along the circumference, which tend to induce a kneeling phenomenon in which the spun filaments bend at the outlets of the spinning orifices. If the structure of the spinneret is modified so as to cause the surface lubricant to flow down toward the center of the spinneret, various problems may arise, for example, in that the discharge pipe provided for the purpose of withdrawing the surface lubricant may come into contact with the spun filaments. Accordingly, it is difficult to use this spinneret for practical purposes.
Japanese Patent Publication No. 2492/'69 discloses a spinning method in which the spinneret face is provided with a porous part made of a porous metal or the like and a surface lubricant is introduced into the spinning orifices by infiltrating the surface lubricant into the porous part. However, this method tends to cause an uneven distribution of the amount of surface lubricant infiltrated. Especially in the neighborhood of the site at which the surface lubricant is introduced, the surface lubricant drips down and thereby exerts an adverse influence on the spinning. Moreover, although the porous part is made so as to form part of the spinning orifices and give a divergent shape to the outlets thereof, the amount of the surface lubricant may vary along the circumference of the spinning orifices to induce a kneeling phenomenon Furthermore, this method has the disadvantage that the presence of irregularities in the spinneret face makes its cleaning difficult and the porous metal may be clogged with the spinning solution, gas or cleaning agent. Thus, this method fails to bring about the desired result and cannot readily be put to practical use.
Japanese Patent Laid-Open No. 143719/'78 discloses a spinning method in which a surface lubricant is introduced through an annular distributor disposed on the peripheral region of the spinneret. This method enables the surface lubricant to be more or less effectively introduced to the aforesaid peripheral region However, it is difficult to introduce the surface lubricant to the central region of the spinneret. Thus, this method still fails to introduce the surface lubricant uniformly to the whole spinneret.
Japanese Patent Laid-Open No. 158311/'80 discloses a spinning method in which a surface lubricant is introduced by means of a distributing plate having grooves which is disposed on the peripheral region of the spinneret or on the whole spinneret face except the spinning orifices. In this method, flow channels are formed by pressing the groove-bearing side of the distributing plate against the spinneret face. However, this method requires a spinneret device having a very complicated structure. Moreover, when the distributing plate having grooves is disposed on the whole spinneret face except the spinning orifices, it becomes difficult to correct (or clean) the spinneret face.
In order to supply the surface lubricant to the spinneret, a feeding method utilizing the head of a surface lubricant tank and a feeding method using a metering pump are commonly employed. However, when the former is employed to supply the surface lubricant, the feed rate may vary because of difficulty in keeping the head constant. On the other hand, when the latter is employed, the feed rate can be stabilized. However, this method has the disadvantage of requiring a considerable equipment cost.